Hydraulic shock absorber



Patentedgoct, 2 0, 1925.

UNITED sTAT'EsAPATENT,orner.

ISAAC MACKLINLADDON AND FREDERIC E. E LDR, 0F DAYTON, OHIO.

HYDRAULIC sHocx ABsoRBE'R.

Application led .Tune 27, 1923. Serial No. 648,022..-

TaaZZ whom it may concer-nf Be it known that lwe, ISAAC M. LADDoN and FREDERIC E. FLADE'R, citizensl of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new-and useful Improvements in Hydraulic Shock Absorbers, of which the following is al specification.

This invention relates in generalto shock absorbing means for use on vehicles and more particularly, concerns the "provision of hydraulic shock absorbing means for use on airplanes. -v

We are aware it is not new in the art to provide hydraulic shock absorbers foraircraft. It has been proposed to usel a hydraulic shock absorber embodying 'the principleof a l dash pot forrelieving the initial Shock of landing. As far as we are aware, however,

there has been no adequate provision made for returning the shock absorbing means to its operative position after the shock has been absorbed.

It is an object of our invention to vprovide I a hydraulic shock absorber which utllizes the principle of the dash pot in absorbing the shock or shocks of landing and to so y adapt our device that the rotation of the vhereinafter described. A

axle of the landing gear of such an aircraft is used as a means forproviding motion to elements for restoringthe shock absorbing device to its operative position, lthat is, to

-such a 'positionthat it will -be ready to receive and absorb further shocks.

Other objects of our invention will appear in the accompanying. specifications and claims and will be disclosed inthe accom-.

panying drawings in which;.

Figure 1 is a side elevation largely in central vertical section of my device.

Figure 2 is a central vertical section taken at'right angles to lthe ure 1.

Referring with greater plarticularity to the drawings, it will be seen' t at we have provided a cylinder 1 rigidly secured to the landing gear chassis. 10 having a' lower skirt portion 2, in which there is provided an an.

nular channel or guideway in which a cylinder sleeve 4 is adapted to be rec1procated.

The cylinde; 1 is provided on its-right hand side as viewed in Figure 1 with a fluid .passageway 5, the purpose ofwhich will be port '6 1n the sleeve 4 is adapted'to communicate with the view shown in Fig-- in the inner w'all'of the cylinder 1. u

The sleeve 4 is mounted at 4a upon the axle 8 ofthe airplane, suitable means for making this 'bearingfluid-tight being provided. A piston, 14 fixedly secured to a piston rod 13, which in turn is secured to a ring 11, is eccentrically mounted on axle 8 by means of an eccentric or camL 9 rotating with the axle. The pis-ton 14 is adapted to reciprocate inthe vbore 15 of ,the cylinder- 1,

having a fluid tight fit therein. An outlet valve 16 is provided for the passageway 5,

this valve being spring-seated, the tension i ofthe spring being in excess of that required to support the Weight of the airplane. The plston 14 is provided with passageways 18 downwardly opening valve 19 are thus provided. Between the piston', 14 and the inwardly turned lower end of the cylinderl,`

thereis thus left a chamber 20.

It is to be understood that we do not intend that our inventionl shall be limited to the take up the shock in landing. 4The airplane being attached to the cylinder l there will, upon landing, necessarilybe arelative motion between the cylinder 1 and the sleeve 4 with the result that the fluid in the liuid chamber as shown at 21, will be forced outwardly through the port, tapered slot 7, passageway 5, valve 16,'and 'into the interior of the cylinder 1. Due tothe taper in the slot 7, a gradually increasing resistance will be offered to the relativemotion. The air lane then being on the ground the axle 8 wil rotate, the'ecoentric 9 causing recip rocatorymotion of the piston 14 in the bore 15 of the cylinder 1. 'On the upstroke of the piston the valve 17 will be forced open and the oil ab'ove the piston will be forced downwardly intothe chamber 20. On the downstroke of the piston, the valve 17` will close 'and the valve 19 open, the oil in chamber 20 passageway' 5 through the tapered slot 7 and. a downwardly opening spring-seated valve 17. The lower end of the inner borel vof the cylinder 1 ,is turned inwardly, and ports 23 normally closed by a spring-seated thus being forced out into the interior 9.1 of the sleeve 4. vSince'the sleeve will be lilled with oil, the downward motion of the piston will force the cylinder l upwardly along the sleeve 4 until the two parts are in the same relative position that they occupied before vvehicles, a dashpot shock absorben and means for restoring said shock absorberto its operative position after the shock has been absorbed. v

2l In a shock absorbing means for use on vehicles, a dashpot shock absorber and means operated by the motion of the vehicle for restoring said shock absorber to its operative position after the shock has been absorbed. 3. In a shock absorbing means for use on i'vehicles, a dashpot shockA absorber and means operatedby the motionof the vehicle for restoring said shock absorber to its operative position after tlre shock has been absorbed, said last named means' offerin a brake effect to the motion of said ve icle.v

4. In a shock absorber for airplanes, hy draulic shock absorbing means to absorb the shock of landing, and means operated by the rotation of the airplane aXle to return said shock absorbing means to its operative position after the shock has been absorbed.

5. In a shock absorbing device for use on aircraft, a cylinder fixedly secured to the landing gear chassis of'said aircraft, a cylindrical fluid containing sleeve adapted to be reciprocated in an annular guideway in said cylinder, said sleeve being mounted on the aXle of said aircraft in such a manner as to permit rotation of said axle, a fluid passageway in said cylinder, a port in said sleeve adapted to communicate with said passageway, a spring seated valve in said passageway, a. piston eccentrically mounted 'onsaid axle, valvemeans between said sleeve and said cylinder, and valve means in said piston.

6. In a shock absorbing device for use on v aircraft, a cylinder fixe'dly secured to the landing gear chassis of said aircraft, a cylindrical fluid containing sleeve adapted to be reciprocated inan annular guideway i'n said cylinder, said sleeve being mounted on the axle of said aircraft in such a manner as to permit rotation of saidaxle, a fluid passageway in said cylinder, a port in said sleeve adapted to communicate with said passageway through a ltapered slot therein, a spring seated outlet valve in said passageway, a piston eccentrically mounted on said axle, valve means between said sleeve and said cylinder, and valve means in ysaid piston.

7. In a hydraulic shock'absorber for vehicles, a cylinder adapted to be secured to the undercarriage of said vehicle, an annular cylindrical Vgui'deway and a cylindrical bore in said cylinder, a fluid containing member mounted on the aXle ofsaid vehicle and having a sleeve adapted to reciprocate in said guideway, a piston in said fluid containing member and eccentrically mounted on said axle, and valve means in said piston and said cylinder.

8. In an absorber for use on aircraft hav-l ing a landing gear including a rotary member, a pair of relatively movable shockv absorbing members, and means operable by the rotary member of the landing gear for returning the shock absorbing members to their operative position after the shock has been absorbed. i

In testimonywhereof we affix our signatures.

ISAAC MACKLIN LADDON. FREDERIC E. FLADER. 

